Fiter design is the process of designing a filter.

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FIR filter design for response inside unit circle

I would like to design an FIR filter such that its Z-transform has a certain profile in certain regions. For example, if I'd like to have an FIR filter that nulls the decaying exponential ...
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53 views

What is the name of the following 1st order high-pass IIR filter?

What is the name/family behind the following high-pass IIR filter: $ T = 1/f_s \\ f_c = 5 \\ c_1 = \displaystyle \frac{1}{1 + \tan(\pi f_cT)}\\ c_2 = \displaystyle \frac{1 - \tan(\pi f_cT)}{1 + ...
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61 views

Complex low pass filters

I am searching for documentation on the behaviour of complex low pass filters, and their application in telecommunications. Thank you
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76 views

Are noncausal filters ever used in practice?

Basically what it says in the title; I have just started reading about these things and find noncausal filters pretty interesting in concept, but also they do not seem like they would have any ...
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17 views

Design of butterworts filter by Impulse invariance method

i have an order of 4 how do I break down the 4th order butterworth polynomial to apply impulse invariant method? I want the digital signal. H(z)
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18 views

Formula to get the sui length of Blackman Harris Window

I was reading that I can to obtain the (N) length of Window function. if I have defined: ...
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76 views

Get the distinctive deltas of quite noisy and very variable / dynamic measurement values

for my thesis I need to point out the distinctive deltas of my measurements for further use. The jumps can occur with different heights over different time slots. And the absolute base values can ...
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2answers
49 views

Additional peak after resampling

I prepared a Matlab script, which re-samples spectrum from 24kHz to 20kHz. When I used up-sampling, a fir filter, and then up-sampling again at the end, I get an additional peak at 4kHz which is not ...
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70 views

What are the differences between notch filter & Goertzel?

I would like to integrate in my application a tone detector but I'm confused between 2 kinds of filters: Goertzel or Notch? I saw that Goertzel is a recommended for tone detection. But - what if I ...
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64 views

Any good C# library for signal processing?

Does anyone can link me to a good C# DSP library? I saw some good C++ libraries but I don't have much with C++. Is there any way to wrap them ? My main porpuse is to apply some filters(Lowpass, ...
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55 views

What is Single pole filter?

Can anybody tell me why do we use single pole filter? And may be an example of Single pole filter in matlab. Good literature recommendations are also welcomed.Moreover, that would be good if anyone ...
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89 views

How to test digital filters?

First the question(s): How should I write unit tests for a digital filter (band-pass/band-stop) in software? What should I be testing? Is there any sort of canonical test suite for filtering? ...
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26 views

How to determine cut off frequency for high pass filter using spectral density?

I have filtered out the low frequency noise from the signal. For further analysis, I want to compare it with FIR filters (for which I require cut off frequency). Hence, I took the power density ...
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34 views

Fir filter not working according to frequency response

I have designed a FIR filter with following parameters fs=30, f_pass1 = 1, stop1 = 0.5, f_pass2 = 3, f_stop2 = 4, A_pass = 1,A_stop = 40 Here is code : ...
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11 views

Difference between Sparse filters and Multiplier filters

I googled this differences but i haven't get any exact resources about this.Some papers said Sparse FIR filters, others Multipliers FIR filters.But no one said whether this is same or not. So my ...
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36 views

How to normalize predesigned IIR filter coefficients to have unity gain?

There is a low pass filter with difference equation already provided. $$ y_n = (x_n - 2x_{n-6} + x_{n-12}) - (-2y_{n-1} + y_{n-2}) $$ $$ a_0 = 1, a_1 = -2, a_2 = 1 $$ $$ b_0 = 1, b_6 = -2, b_{12} = ...
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19 views

Identify correlated colored noises that affect a signal

In the process of signal + noise, which is not stationary. In this case how could I a. determine what autocorrelated noise colors affect a signal. b. What mix of correlated colors affect the signal ...
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2answers
75 views

How to design an inverse for a Butterworth low-pass filter?

I have a signal that has a spectral shape very similar to the transfer function of a second-order lowpass filter (butterworth design). I would like to whiten the spectrum of this spectrum in the ...
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34 views

Filter implementation and alternatives

I'm learning of digital filters and found a question asking why a filter with a impulse response $$h[n]= \begin{cases} \frac{1}{n^2+3n+2} & n\geq 0 \\ 0 & n<0 \\ ...
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51 views

Possible to implement simple IIR filter with greater than 6 db/octave slope?

I am using the following IIR code as a low-pass filter in a software project, and it works great. However, I would like the slope of the filter to be much steeper as the one here seems to be very ...
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40 views

What is the Reference tap of an equalizer (FIR Filter)

Currently I'm using the built-in Equalizer (EQ) object from Matlab to equalize my signal. For the EQ there is a parameter called the Reference tap. With different value of the reference tap i got also ...
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41 views

Necessity of Cyclic Prefix in OFDM

I have a question on CP-OFDM. In recent years people are talking about filter bank approach where they are trying to filter out the out of band side lobes using filters. Besides they are presuming ...
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36 views

Any simple Digital All-Pass Filter Design Tools?

I would like to be able to implement an All-Pass filter with a frequency-dependent group delay. I need a maximum group delay at low frequency of about 20 samples (for Fs = 44.1kHz), and it needs to ...
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107 views

Which filter for an audio equalizer

I’m new to DSP and I have to do an audio equalizer in c++. I did a lot of research about it and tried some stuff in the last month, but I’m a little overwhelmed with all those informations and it’s ...
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37 views

Deriche recursive filter using OpenCV

Is it possible to create a Deriche recursive filter using opencv (the Deriche filter is a blur that minimizes noise and preserves edges for later edge detection)? I can create one using CPU code, but ...
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68 views

ECG noise filtering using FIR Bandpass Filter

I am new to signal processing and examine ECG data corrupted with noise. The clean data has a frequency spectrum like this. And the corrupted one looks like this (sorry for the different scale) ...
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33 views

Help with Hankel Tranform filters

I found a filter for Hankel Transform . As far as i understand this is effectively used as an approximation for J0(x) and J1(x) . But how will the change in input affect these filter terms (eg J0(r) ...
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32 views

Equiripple Filter-Design

I have a requirement to design minimax filter with linear programing (linprog in MATLAB). To build the filter I must choose vector $\omega$ (frequency sample), how ...
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104 views

Sampling frequency and oversampling factor

A quite naïve question. I need some clarification regarding choosing the sampling frequency and oversampling factor. The scenario is as follows: I have an OQPSK modulated sequence with symbol rate 2 ...
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26 views

Can't make a Wiener filter work

I have two wav signals, one desired and the other one an unwanted signal perturbing the first one. I'm trying to implement a Wiener filter to reduce the second one, but when using the sound function I ...
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65 views

Find Stopband Edge Frequency

I tried to find the stopband edge frequency.I know that the signal amplitude falls to -3 dB below the passband edge frequency.I examine a lot of DSP books so i don't any information about how to ...
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62 views

Half Sine Pulse Shaping design

The standard of 802.15.4 specfies the following 'The chip sequences representing each data symbol are modulated onto the carrier using O-QPSK with halfsine pulse shaping.' For pulse shaping the ...
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57 views

What windowed Sinc might be closest to a Parks–McClellan low-pass filter?

In another question on dsp.stackexchange, a statement was made that the output of MATLAB firpm() or firls() for an anti-alias low-pass filter was "close" to the coefficients of a windowed-Sinc ...
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49 views

time domain non stationary time series individual colored noise identification algorithm

One of the methods for identification of modulated colored (stationary) noises is that of lag 1 autocorrelation power law noise identification algorithm. This method can determine the dominant noise ...
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17 views

Calculating the network function of a filter

Given a system, that behaves as a 1st order filter with network function $H(s)$. We input: $$v_1 (t)=1+3\cos(10^4 t)$$ And we obtain as output: $$v_2(t)=1+1.5\cos \left(10^4 t ...
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44 views

Convert low pass continuous time filter design to bandpass, discrete time

I am trying to convert the continuous time transfer function of a second order lowpass Butterworth filter is given by: To a bandpass fourth order bandpass digital filter, I first apply the mapping ...
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21 views

Filtering with Gaussian Shape

I would like to know how to properly filter a cosinus wave signal with a Gaussian Filter. I thought to use 'conv' to perform it. My code as follows : ...
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Parks-McClellan - compiling C++ code from Iowa Hills page [closed]

I am trying to compile C++ code for FIR filter design using Parks-McClellan algorithm from http://www.iowahills.com/Example%20Code/NewParksMcClellan.txt . However, I cannot find the following header ...
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143 views

How do can we cancel out noises while listening voice on headphones?

It's a common problem that while talking with the another person on Smart phones with the help of regular headphones,we get very annoying sounds at background . The opposite person's voice gets mixed ...
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56 views

Help choosing coefficients for a simple FIR filter to extract DC component

I am a beginner in design of digital filters... I have just completed Coursera's Linear Circuits course! I have a signal which is sampled at 50 Hz where the DC component has a value of 800000 and ...
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52 views

What is sound output delay of a band pass filter at different freqencies?

I measured that a 2-pole band pass filter, given imput audio of different frequencies, outputs an audio signal with different time delay. At 440Hz, the time delay between of the input audio and the ...
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1answer
17 views

Concepts Surrounding First Two Samples in Difference Equation

I'm attempting to construct a difference equation in matlab for the function u(n) and find the auto-correlation matrix R. I'm following the technique as is defined by my text below: The system I'm ...
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80 views

Design Filter with Arbitrary Magnitude and Phase Response in Matlab

Does anyone know of a way to design a filter with arbitrary magnitude and phase response in Matlab?
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Phase Linearization

Does anyone know of some simple algorithms to linearize the phase response of a filter. I have a notch filter with a non-linear phase response. I basically need an all pass filter (so that the ...
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23 views

high amplitude filter for same frequency signals

I'm analysing quasi-periodic movement (push ups). Each push up can take 1-5 seconds with stops or jerky movement along the way. I already used Savitzky-Golay filter. I want to filter out low ...
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41 views

How many different filters are needed for in an iterated filter bank?

I'm trying to implement an iterated filter bank as described in the Subband coding chapter of the Really Friendly Guide to Wavelets. However, the text seems to suggest that The advantage of this ...
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1answer
50 views

Matlab: is a highpass filter what I want, to obtain my required spectrogram? How do I design/apply this? (pic included)

The axes are wrong in the spectrogram. I have an audio wav file, and I know the sampling rate. this is read into the audioData variable. The audio is 1 channel. selected window length I believe (can't ...
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98 views

FIR design using firpm (Parks-Mclellan)

Can you please help me with some ideas on how to implement an FIR filter in Matlab using Parks-Mclellan algorithm? My specifications are the passband cut-off frequency, the transition bandwidth. The ...
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30 views

Filter signal1 from evolving frequency response of signal2

I'm a composer (of music) starting out with signal processing. I'm also reasonably proficient in C at this point. I'm not even sure if what I'm trying to do is possible, because I can't yet find an ...
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266 views

FIR filter coefficients from frequency responses

I have frequency responses of FIR filter of order 13 from obtained 50 frequency samples. How can I get FIR filter coefficients of order 13? For example, in MATLAB a lot of possible ways I tried ; I ...